Chili peppers are the fleshy fruits of small shrubs of the genus Capsicum, members of the nightshade family, Solanaceae. They contain various vitamins depending on the species. Their spongy interior placenta (commonly called ribs) is where the fruits develop their characteristic heat-producing chemical, capsaicin. Some capsaicin coats the seeds and circulates to the fleshy shell but to a lesser degree.